Despite shortfall from ‘full pool’ lake up 4.3 feet with help of rains

LAKE LANIER – The U.S. Army Corps of Engineers reports that substantial rain so far this summer has added 50 billion gallons of water to Lake Lanier. Yet the lake level is still far short of being deemed full.

Lake Lanier is still short of the “full pool” goal of 1,071 feet, standing at 1065.3 feet now. The Corps of Engineers reports the sustained rainfall and other conservation efforts have raised the lake’s pool by 4.3 feet (about 50.3 billion gallons). As a comparison, all the water in all of the Atlanta Aquarium’s tanks amounts to just 10 million gallons.

Despite rumors that the Corps of Engineers, which manages the lake, is keeping the lake’s pool at a lower level due to “some construction on the North end of the lake” that simply isn’t true, said one Corps official.

“We have heard that same story, but that is false,” the official said.

The Corps’ Deputy Public Affairs Officer Tim Oberle said Lanier’s level is 6.7 feet below full pool. Heavy rainfall since mid-March has helped immensely, adding four feet to the level, but a lot more rain would be needed to reach full pool – about 68 billion gallons.

The Corps of Engineers is not intentionally keeping the reservoir below the summer level of 1,071. The goal is to refill the reservoir every year, Oberle said.

Lake Lanier’s continued health is critical to the sustainability of the entire Atlanta region. The impact of its loss as a resource would be difficult to say – dominoes would be falling everywhere.

Nevertheless, a 2012 economic impact study done by the 1071 Coalition – a group comprised of civic groups, businesses, concerned citizens and other entities – determined the loss of Lake Lanier as a resource would be an economic loss of $35 billion to $40 billion annually.

The region’s dependence has only grown since then.

Lanier, in addition to being the engine to produce potable water for the Atlanta region, it serves as a magnet for real estate development, recreation and leisure and allows Atlantans to flush their toilets.

The Corps of Engineers is not blind to these facts and is devoted to protecting the reservoir both as a valuable recreation source and an invaluable potable water source.

“The combination of conservative operation and increased rainfall has resulted in higher levels at the reservoir. Continual rainfall above the dam needs to occur in order to refill the reservoir to the summer target level of 1,071,” Oberle said.

Corps officials point out Lanier is shaped like an inverted pyramid. That means as the lake is filled, it takes considerably more water to replenish it at the top where the lake’s surface is at its greatest than it did say 20 feet lower. In other words, it takes considerably more water to move the needle the closer it gets to full pool.

Oberle said the difference in gallons of lake water at 1,065 feet and 1,066 feet is 11.73 billion gallons. So the lake must capture roughly another 68 billion gallons of water.

“Continual rainfall above the dam needs to occur in order to refill the reservoir to the summer target level of 1071,” Oberle said.

Hindering that is the fact that Lanier captures rain runoff from a relatively small area compared to the water it releases below.

The Corps must also release water downstream regularly to accommodate downstream users in the greater Atlanta area and points south.